Authorities declared an Ozone Action! Day for metropolitan Detroit today, but not for Toledo.
The alert area includes Monroe County and six other southeastern Michigan counties.
Residents and motorists are asked to curtail activities that contribute to hydrocarbon pollution in the air, including driving, fueling vehicles during the daytime, using lawn mowers and other equipment with small gasoline engines, and barbecuing with lighter fluid.
Sunny, hot conditions, such as are forecast for today, accelerate reactions that create ozone in the lower atmosphere, where it is a health hazard.